This paper presents the subject of the expansion process of roman citizenship culminating in the Severan Dynasty. The origin and government of Septimius
Severus and its successors are analyzed,especially those of Caracalla, studying themain decisions of his government related to citizenship, emphasizing the
Constitutio Antoniniana and its various historical interpretations and it is political and cultural significance. Finally, the article mentions the transformation of the meaning of citizenship in the subject concept under the Late Empire.